This code simulates data

psi $<-0\mathrm{.}6$

p $<-0\mathrm{.}4$

z $<-$ array$($NA$,$dim$=300)$

y $<-$ array$($NA$,$dim$=$c$(300,5))$

for$($i in $1$:$300)\{$

z$[$i$]<-$ rbinom$($n $=1,$ size $=1,$ prob $=$ psi$)$

$\}$

p$.$eff $<-$ z $*$ p

for $($i in $1$:$300)\{$

y$[$i$,]<-$ rbinom$($n $=5,$ size $=1,$ prob $=$ p$.$eff$[$i$])$

$\}$

How many sites are there in the simulated data?